Measuring keyboard response delays by comparing keyboard and joystick inputs

The response characteristics of PC keyboards have to be identified when they are used as response devices in psychological experiments. In the past, the proposed method has been to check the characteristics independently by means of external measurement equipment. However, with the availability of different PC models and the rapid pace of model change, there is an urgent need for the development of convenient and accurate methods of checking. The method proposed here consists of raising the precision of the PC’s clock to the microsecond level and using a joystick connected to the MIDI terminal of a sound board to give the PC an independent timing function. Statistical processing of the data provided by this method makes it possible to estimate accurately the keyboard scanning interval time and the average keyboard delay time. The results showed that measured keyboard delay times varied from 11 to 73 msec, depending on the keyboard model, with most values being less than 30 msec.     

Error detection and correction in a structured movement task

Error-detection and error-correction experiments were conducted to examine the assumption that organizational processes play an important role in motor learning and control. During the initial phase of each experiment, the sensory aspects of five movements were held constant while the organizational structure (sequential vs. random) of the movements was varied. In the learning phase of both experiments, the effect of organization produced increased reproduction accuracy for the structured movement sequences compared to those that were random. This benefit of organization carried over into the error detection and correction parts of the experiments where it was shown that improved error detection and correction capabilities were assisted by the manner in which the movements were presented. The importance of cognitive processes is discussed in terms of past and contemporary accounts of motor learning and control.     

Inspection time and response strategies in a choice response task

The effects of varying stimulus duration on two response measures, percentage correct (p_c) and mean reaction time (RT) were investigated in a lights-keys RT task similar to an inspection time (IT) task. One of either N = 2, 4 or 8 lights came on as the stimulus, followed after a range of stimulus exposure durations (D) by all 8, as a backward mask. It was found that p_c was an ogival function of D for all three levels of choice, and that the standard deviations of the best-fitting normal ogives were equal. It is argued that the standard deviation can be taken as a measure of the neural noise, or error-inducing variability introduced by processing the stimulus, and so this result indicated that noise in the choice reaction task is independent of N. The effect of D on RT was as predicted by an optional accumulator model for 7 Ss with RT decreasing as D increased, while another 2 Ss appeared to have adopted a temporal deadline criterion giving RTs independent of D and equal error and correct RTs. The same two response styles were found in a re-analysis of RT data from an IT study. The p_c vs D curves were comparable for both response styles. The accumulator model commonly assumed to underly IT tasks thus does not describe the behaviour of all Ss. Such individual differences in strategic approach to the IT task should be investigated further, since assuming that all Ss use one approach may hide or confound relationships between IT and other measures of individual difference, such as intelligence. Recommendations for better IT measurement techniques are given.     

Alternate response preparation in a visuomotor serial task

The preparation of a particular motor pattern is related to the information available that enables the actor to predict the correct response to a forthcoming stimulus. In many situations, however, prediction is not possible. In such cases, the individual can guess the probable parameters of the next stimulus. The authors attempted to establish the bias in the motor intention for movement and its interaction with a possible memory trace of the stimulus-response mapping produced by the preceding stimulus. Two letters were presented bilaterally, and participants (N=21) had to discriminate the target letter and respond with the compatible hand. The present findings support the existence of a memory trace of the previous stimulus-response mapping.     

Stimulus and response anticipation in a serial reaction task

When subjects are confronted with sequences of stimuli that are constructed according to certain rules, they tend to improve their performance in terms of lower error rates and/or faster reaction times as compared to random sequences of the same stimuli, even if they are not able to report the regularities of events.     

On spatial response code activation in a Simon task

The Simon effect refers to the performance advantage for trials where the task-irrelevant location of a target spatially corresponds with the location of the response. It is thought that the irrelevant spatial code of the target facilitates responding by automatically pre-activating the spatially corresponding response code. This spatial code is thought to passively decay shortly after its activation. In this investigation, the response was selected according to the identity of a central cue. The selected response was executed or withheld depending the identity (Experiment 1) or the presence (Experiment 2) of the target. Varying the stimulus-onset asynchrony (SOA), between the central response cue and the peripheral target, allowed for a time-course analysis of the Simon effect. The results of two experiments provided no indication that the activation level of the irrelevant spatial code decayed while the relevant response was prepared. Although reaction times increased as the SOA decreased, the Simon effect was additive with SOA, suggesting that the automatic activation of the task-irrelevant spatial code was delayed until the task-relevant response code was mostly prepared, perhaps due to the capacity limitations of response selection.     

Some types of error in a choice response task

Errors from a serial response task involving single-finger responses to alphabetic stimuli are analysed and discussed in relation to findings which have been reported from tasks with more compatible stimulus-response relationships. Errors are divided into three distinguishable subsets and in each case found to have longer latencies than correct responses. Those which result from mirroring the required response about the centre of the hand are found to resist elimination during practice and their frequency seems to depend on the type of code used. In all cases error correction times are faster than the times to make a correct response but mirror errors and errors involving a finger adjacent to the correct response are corrected faster than other errors. The findings are discussed in relation to the theory of choice reaction time and error correction.     

Movement observation affects movement execution in a simple response task

The present study was designed to examine the hypothesis that stimulus-response arrangements with high ideomotor compatibility lead to substantial compatibility effects even in simple response tasks. In Experiment 1, participants executed pre-instructed finger movements in response to compatible and incompatible finger movements. A pronounced reaction time advantage was found for compatible as compared to incompatible trials. Experiment 2 revealed a much smaller compatibility effect for less ideomotor-compatible object movements compared to finger movements. Experiment 3 presented normal stimuli (hand upright) and flipped stimuli (hand upside-down). Two components were found to contribute to the compatibility effect, a dynamic spatial compatibility component (related to movement directions) and an ideomotor component (related to movement types). The implications of these results for theories about stimulus-response compatibility (SRC) as well as for theories about imitation are discussed.     

Online response preparation in a rapid serial visual search task

Online response preparation was assessed in a visual search task using rapid serial visual presentation. In each trial, a series of letters was presented sequentially, and participants were instructed to make a target-present response if a prespecified target letter was presented or a target-absent response if it was not. Measurements of response preparation using both probe reaction time and the lateralized readiness potential indicated that preparation of the target-absent response increased near the end of the sequence. Most of the increase appeared to be due to direct priming of the target-absent response by nontarget letters, but part was due to the increased conditional probability of this response near the end of the sequence. These results extend previous studies of response preparation by showing online response preparation during a temporally extended reaction time task.     

Changes in spinal reflex excitability in a countermanded timed response task

Subjects (N = 8) performed a timed response task in which they attempted to synchronize an impulsive foot-press response with the last in a series of four regularly spaced tones. In Experiment 1, the response was countermanded on one third of the trials (stop trials) by a stop signal that appeared at a predetermined delay after the third tone. No stop signal appeared on the remaining trials (go trials). All subjects showed a systematic transition from withholding the response on stop trials in which the stop signal appeared shortly after the third tone to executing the response on trials in which a single stop signal delay had been chosen so that a response would be made on about 50% of the stop trials. We elicited Hoffmann (H) reflexes from the soleus muscle on all trials to determine whether the reflexes were augmented on occasions on which a response was prepared but withheld. Mean H-reflex amplitudes on go trials and on stop trials on which the response was executed were similar and showed a marked augmentation beginning about 250 ms before response onset; mean H-reflex amplitudes on stop trials on which the response was withheld showed less pronounced augmentation. Inspection of individual H-reflex amplitudes revealed that on stop trials on which the response was withheld the reflexes could be augmented to the same extent as on trials on which the response was executed. This dissociation of H-reflex augmentation and response execution shows that H-reflex augmentation reflects a controlled response process. Ballistic response processes therefore must be limited to a brief duration.     

The influence of response grouping on free-choice decision making in a response selection task

Previous research has demonstrated an advantage for the preparation of fingers on one hand over the preparation of fingers on two hands, and for the preparation of homologous fingers over that of non-homologous fingers. In the present study, we extended the precuing effects observed with finger responses to response selection under free-choice conditions. Participants were required to choose from a range of possible responses following the presentation of a precue that indicated which response to prepare (go-to precue) or prevent (no-go-to precue). In Experiment 1 the choice was between homologous and non-homologous finger responses on the hand opposite to the precue while in Experiment 2 the choice was between finger responses on the same or different hand to the precue. In the go-to precue condition, the frequency of homologous finger choices was more frequent than non-homologous finger responses. Similarly, participants chose finger responses on the same hand as the precue regardless of whether they were instructed to prepare or prevent the precued response. The hand effect bias was stronger than the finger effect bias. These findings are consistent with the Grouping Model (Adam, Hommel, & Umilta, 2003).     

Validating a visual version of the metronome response task

The metronome response task (MRT)—a sustained-attention task that requires participants to produce a response in synchrony with an audible metronome—was recently developed to index response variability in the context of studies on mind wandering. In the present studies, we report on the development and validation of a visual version of the MRT (the visual metronome response task; vMRT), which uses the rhythmic presentation of visual, rather than auditory, stimuli. Participants completed the vMRT (Studies 1 and 2) and the original (auditory-based) MRT (Study 2) while also responding to intermittent thought probes asking them to report the depth of their mind wandering. The results showed that (1) individual differences in response variability during the vMRT are highly reliable; (2) prior to thought probes, response variability increases with increasing depth of mind wandering; (3) response variability is highly consistent between the vMRT and the original MRT; and (4) both response variability and depth of mind wandering increase with increasing time on task. Our results indicate that the original MRT findings are consistent across the visual and auditory modalities, and that the response variability measured in both tasks indexes a non-modality-specific tendency toward behavioral variability. The vMRT will be useful in the place of the MRT in experimental contexts in which researchers’ designs require a visual-based primary task.     

A speeded coding task using a computer-based mouse response

This study assessed whether a speeded coding task that used a computer-based mouse response (CBMR) format was a measure of general processing speed (Gs). By analyzing the task within a network of tasks representing both traditional Gs tests and reaction time tasks, it was shown that a CBMR test can be used to measure the same construct as traditional paper-and-pencil (PP) tests and that this response format does not introduce variance associated with psychomotor performance. Differences between PP and CBMR formats were observed, and it is argued that these may provide information on individual differences in performance not available from traditional coding tests.     

Facial action patterns, electromyography, and moods in response to an insoluble task as a function of sex and sex-role differences

College students of either androgynous or sex-typed orientation were randomly assigned to either an insoluble concept-formation task or a solvable one. Posttreatment scores were compared for measures of dysphoric mood (Multiple Affect Adjective List), electromyographic responses (corrugator and zygomatic), and discrete facial responses (Facial Action Coding System). In Study 1, 18 androgynous women were compared to 16 feminine women; in Study 2, 16 androgynous men were compared to 16 masculine men. The insoluble task was associated with more corrugator activity (frowning) than the solvable task in both studies. Feminine women displayed more corrugator responses across both tasks than androgynous women. However, masculine men did not differ from androgynous men in over-all corrugator response activity. Androgynous women smiled more than feminine women on the facial action coding measure. Men subjected to the insoluble task reported significantly more anxiety, depression, and hostility. Masculine men scored higher on anxiety during the insoluble task than androgynous men, while the latter scored somewhat higher on anxiety in the other condition.